Trajectory Tracking Control of an Underwater Swimming Manipulator with System Constraints and Uncertainties

The underwater swimming manipulator is a new type of underwater vehicle manipulator composed of an underwater snake robot and several thrusters. In this paper, trajectory tracking control is considered for the underwater swimming manipulator with system constraints and uncertainties. Firstly, a linear model predictive controller with control input constraints is designed via feedback linearization to realize the constraints on joint torque and thruster forces. Secondly, the system uncertainties are estimated in real time based on the off-line Gaussian process regression and an adaptive extended state observer, and the estimated results are applied to the closed-loop control system for compensation. Finally, the stability of the closed-loop system is proved, and the simulation shows that the proposed method can realize the high-precision trajectory tracking control of the underwater swimming manipulator and meet the actual constraints when considering the system uncertainties.